Furnace.



No. 635,3l8.

(No Model.)

B. C. HEAVEY.

FURNACE.

Patented Oct. 24, I899.

(Application fileiApr. 12, 1 897.)

3 Sheets-Sheet I I, r N 1 172062220 3 1 Ward QJkQ-yg N0. 635,3l8.Patented Oct. 24, I899.

B. C. HEAVEY.

F U B N A0 E.

(Application filed 4 1-. 12, law.

3 Sheets-Sheet 2,

Zahara? afiladg No. 635,348. Patented Oct. 24, I899.

B. C. HEAVEY.

FURNACE.

(Application filed Apr. 12, 1897.)

3 Sheets-Shoat 3,

(No Mb'dal.)

m: nonms PETERS cc, wumoumow WIH|NGTON, 04 c.

BERNARD C. HEAVEY, OF CHICAGO, ILLINOIS, ASSIGNOR OF FORTY-NINEONE-HUNDREDTHS TO SAMUEL T. WHITE AND JOHN FLAI-IERTY, OF

SAME PLACE; MARIA HEAVEY ADMINISTRATRIX OF SAID BERNARD C. HEAVEY,DECEASED.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 635,318, dated October24, 1899.

Application filed April 12, 1897.

To all whom it may concern.-

Be it known that I, BERNARD O. HEAVEY, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a new and useful Improvement in Furnaces, of which thefollowing is a specification.

My invention relates to improvements in furnaces generally,but moreespeciallyin furnaces intended to burn fuel-dust.

My object is, first, to provide certain improvements in the mechanismfor automatically feeding fuel-dust to the fire-chamber, and, second, toprovide certain improvements in the construction of the fire-chamber ofa boiler-furnace, all to the end of economizing in fuel consumption andin the cost of steam production.

Referring to the drawings, Figure 1 is a vertical longitudinal sectionthrough a boilerfurnace constructed with my improvements; Fig. 2, abroken sectional plan view, the section being taken on irregular line 22 of Fig. 1; Fig. 3, a vertical cross-section taken on line-3 of Fig. 1;Fig. 4, a broken view, partly in section and partly in elevation, of anautomatic fuel-dust feeder constructed for a battery of three furnaces;and Fig. 5, a broken elevation of the front end of the furnace on areduced scale.

My present invention is similar in severalof its main features to thefurnace described in my application, Serial No. 607,916, filed in theUnited States Patent Office October 5, 1896.

A is the front wall of the fire-chamber, having a door t leading to theash-pit B and a door 8 leading to the fire-chamber C.

A is the front of the boiler-chamber.

A A are the side walls of the furnace, A the rear wall thereof, and Athe bridge-wall.

A horizontally-disposed grate B separates the fire-chamber and ash-pit.The fire-chamber projects forward from the front wall A of theboiler-chamber and is provided with a top A This top covers the forwardhalf, more or less, of the fire-chamber, and it, the front A, and theside walls A are constructed of suitable brick. The front A, top A andthe side walls for a distance back about equal Serial No. 631,845. (Nomodel.)

to the length of the top are provided with an embedded casing r ofnon-heat-conducting material, such as asbestos or other suitablesubstance. At the upper side of the firecha mber are forward verticalmanifolds g on opposite sides of the chamber 0 at the inner end of thetop A and corresponding manifolds q extending upward from thebridgewall. Extending between the upper end portions of the manifolds qis a cross pipe or conduit g and extending between the upper endportions of the manifolds q is a cross pipe or conduit g Side pipes 19extend between manifolds q g on the same side, and a series of upperparallel circulating-pipes g extend between the pipes g (1 The manifoldsand pipes constitute a frame D, forming a top for the fire-chamberspanning the grate B between the close top A and bridge-wall.Communicating with the rear end of the boiler E and extending to themanifolds q are circulating-pipes p, and extending from the manifolds gare circulatingpipes 92, which communicate with the front end of theboiler. Fitting upon the circulating pipes or conduits are blocks F, offire-clay or other refractory material, which are placed at intervals orspaced, as indicated in Fig. 2.

The frame D, with the spaced blocks supported thereby, forms a gratedtop for the rear end portion of the fire-chamber, having openings Z leftby the spaced blocks for the escape of products of combustion from thefire-chamber. The grated top tends to hold back the products ofcombustion in the firechamber, so that approximately perfect combustionwill take place therein. Water from the boiler E passes downward fromits rear end through the pipes 19 to the manifolds andcirculating-pipes, forming the frame D, and renters the boiler throughthe pipes at. The circulating-pipes g g are heated directly by theproducts of combustion. The blocks F when once heated tend to store theheat to prevent chilling of the hot products of combustion by thecirculating-pipes. The blocks, furthermore, when once thoroughly heated,will form a hot, almost incandescent, bed below and close to the underside of the boiler.

My improved furnace, as before stated, is

intended for use more especially in burning f uel-dust and particularlythe coal-d ust which accumulates at the mines and has hitherto beenconsidered more or less worthless for fuel.

Extending through the front wall A are preferably two converging andslightly-inclined chutes or deflectors G and G. Above the said wall is acoal-dust-rcceiving tube or hopper 7;, (see Fig. 5,) from the lower endof which extend branch tubes 7;, which terminate in the furnace-wallabove the deflectors G G. In the sides of the branch tubes 7t or tube7;, or both, are air-inlet openings 75. (See Fig. 1.) Extending throughthe front A into the spaces above the deflectors G G and terminating atpoints more or less forward of the lower ends of the branch tubes areblast-pipes 2', extending from a steam-pipe or steam-pipes i,communicating with the steam-supply, which may be the boiler E. Theblast-pipes are provided with drip-cocks 11 and interposed in each pipe11 is a shut-off valve i The chutes or deflectors G G form flaringmixing-chambers and open into the fire-.

chamber, the feed-tubes 7t" entering the tops between the blast-pipesand fire-chamber. By preference the deflectors converge at an angle, theapex of which is a point about midway between the front and rear ends ofthe lire-chamber.

The automatic fuel-feeding mechanism II, which I prefer to employ andwhich is shown in Fig. at, is in the main similar to that shown,described, and claimed in my aforesaid pending application, but isextended to obviate the necessity of any handling of the coaldust afterit has once been deposited into a supply-bin. A tube or conduit 7textends from a storage-bin (not shown) to a supplychamber h. Extendingupward from the top of the chamber 7t is a pipe or chute h ter miuatingin a hopper-shaped compartment 71 Centrally within the pipe 7t is a tube7t, extending from near the lower end of the chamber 7t and provided atits upper end with a hopper-shaped receptacle h. In the tube 7t is aconveyor g, which may be a screw, as shown, and in the tube It is aconveyor 9, which extends from the bottom of the receptacle 7t to apoint above the tube 7D. The hopper 7L5 terminates in a plane below thetop of the hopper its, and the parts are so mounted with relation toeach other that a space f exists around the hopper 71 and tube If in thehopper 7L3 and tube 7L2. Extending from the hopper 7L5 horizontallyacross the front of the furnace or furnaces is a conveyer-tube 71,containing a eonveyer-screw 7LT. In front of each furnace is a hopper ordistributing-receptacle 71/ below an opening in the conveyertube 7t. Atthe end of the tube It is a chute h, terminating at its lower end in aclose receptacle or overflow-chamber h A conveyer-tube 7t extends fromthe lower end of the receptacle h to the upper end of the chamber 7t. Inthe tube It is a conveyer 71, The construction shown in Fig. & isadapted to supply a battery of three furnaces, and the hoppers 7L8 areeach in front of a furnace, the lower end of the hopper being inhorizontal line with the upper end portion of the respective feed-tube7c of the furnace. Extending from the lower end of the respective hopper713 to the respective feed-tube 7a is a conveyer-tube 7t, provided witha conveyerscrew. Each of the conveyer -screws mentioned is upon a shaftprovided with a pulley, the pulleys being belted to a suitable drivingpower, which will turn the screws at the desired speed.

In practice coal-dust is withdrawn from the storage-bin by means of theconveyer-screw 9 through the tube h to the chamber or receptacle 7t.From the receptacle h it is raised by means of the screw 1 to the hopper7L5. Any overflow from the hopper it will descend through the space f tothe chamber 71 The fuel is withdrawn from the hopper h by the screw 71and the hoppers 70* thus kept supplied. When the said hoppers are full,the surplus fuel will be carried to the chute 7L and descend to thechamber 7L), from which it will be withdrawn by the screw h through thetube h back to the chamber h. The conveyor-screws in the tubes 71, carrythe coal-dust from the hoppers h to the feedtubes 7.1. v

In operation the fire is started upon the grate B and. fed with fuelthrough the doors until the fire-chamber is thoroughly heated and anincandescent bed of fuel covers the grate. The conveyer-screws are thenset in operation, and steam is turned in through the blast-pipes. Thecoal-dust, which descends through the feed-tube 7t and branch tubes 7;,falls into the mixing-chambers G G and is sprayed backward into thefire-chamber by the steam-blasts.

In feeding coal-dust to a furnace it is desirable that the amount fedshall be properly proportioned so that it will enter the chamber as fastas, but no faster than, it can be consumed. If it is not fed fastenough, the desired heat cannot be maintained, and if fed too fastperfect combustion will not take place, and more or less unconsumed fuelwill be carried by the draft over the bridge-wall. To produce the bestresults, the fuel must be prevented from caking or entering the furnacein lumps. The conveyer-screws have a tendency to grind the coal-dust andkeep it from caking, though if fed directly by a screw into the furnacethe coal-dust would be more or less packed and prevent evendistribution. In my present construction the steam-blasts in thechambers afforded by the deflectors tend to suck the coal-dust throughthe tubes 7t, at the same time drawing in sufficient air through theopenings 70 to support initial combustion. The forward part of thefire-chamber being more or less close affords a heatstorage chamber, itsheat-storage properties being enhanced by the non-heat-conducting casingr. In practice the heat at the forward end of the furnace becomes sointense that the fuel ignites almost immediately upon entering thechamber, and the streams playing backward from the deflectors appearincandescent. Oombustion of the fuel is increased by causing theincoming streams to meet at about the center of the furnace, where theparticles of fuel strike against each other, intermix, and thus becomethoroughly stirred. Air to support combustion also enters from theash-pit through the grate-bars. With the construction described butlittle judgment is required on the part of an operator to maintain justthe right supply of fuel to effect such perfect combustion thatpractically no unconsumed particles of fuel will escape over thebridge-wall. Thus, while employing fuel of the cheapest character,substantially all the heat-units are utilized and the furnace ispractically smokeless.

WVhile I prefer to employ two deflectors or mixing-chambers, disposed asdescribed, because two streams striking together are of materialadvantage, I do not limit my construction to the use of two deflectorsor mixingchambers.

My improved furnace, constructed as described, is of the best form nowknown to me for producing the best results; but the construction may bevariously modified in the matter of details without departing from thespirit of my invention as defined by the claims.

What I claim as new, and desire to secure by Letters Patent, is

1. In a boiler-furnace, the combination of a fire-chamber provided alongits forward portion with heat-storing sides and top, the top terminatingbeneath the forward end portion of the boiler, a bridge-wall at the rearend of the fire-chamber, water-circulating conduits extending from therear end of said top to the bridge-wall, and spaced blocks resting uponthe said conduits, substantially as and for the purpose set forth.

2. In a boiler-furnace, the combination of a fire-chamber provided alongits forward portion with heat-storing sides and top, the top terminatingbeneath the forward end portion of the boiler, a bridge-wall at the rearend of the fire-chamber, a frame formed of manifolds andwater-circulating pipes communicating with opposite ends of the boilerand extending from the rear end of the said top to the fire-wall, andspaced blocks of fire-clay, or the like, resting upon the saidcirculatingpipes, substantially as and for the purpose set forth.

3. A fuel-dust feeder for furnaces, comprising a supply-chamber h, anoverflow-chamber h a dust-conveyer extending from said' supply-chamberto the overflow-chamber, one or more distributing-receptacles in theline of said conveyer, a dust-conveyer extending from thedistributing-receptacle to the furnace, and an overflowconveyerextending from the lower side of the overflow-chamber back to the saidsupply-chamber, substantially as and for the purpose set forth.

BERNARD O. HEAVEY. In presence of J. H. LEE, R. T. SPENCER.

